Some imaging systems (e.g., camera systems employed in conjunction with virtual reality (VR) or augmented reality (AR) devices) project structured light (e.g., predetermined patterns, such as lines, spots, and so on), whether in the visible spectrum, infrared (IR) spectrum, near-infrared (NIR) spectrum, or another wavelength band, into a local area or environment. An imaging subsystem or device may then capture images of the reflections of the projected structured light from the local area. A control system may then process the images to “map” the local area, such as by determining the distance from the imaging subsystem to each lighted portion of the local area based on the geometry of the reflected light patterns perceived via the imaging subsystem.
In such imaging systems, a diffractive optical element (DOE) may be employed to generate the predetermined patterns that are projected into the local area. Generally, a DOE may be constructed of glass, polymer, or another material that is etched, scored, or otherwise altered so that light passing through the DOE will result in the generation of the structured light pattern. Generally, the higher the resolution of the structured light being projected (e.g., the higher number of identifiable features in the pattern, the closer the features are to each other in the pattern, and so on), the higher the resolution of the resulting map of the local area. Consequently, to provide such structured light, the pattern provided by the DOE is typically of a corresponding high resolution, which may be relatively expensive compared to a DOE providing a simpler, lower-resolution pattern. Additionally, systems using such DOEs may each be limited to projecting a single structured light pattern corresponding to the particular DOE surface features.